1. Field of Invention
The present invention relates to imaging devices, particularly to a stripper blade assembly for removing a print medium from the surface of a roller and/or an imaging drum of an imaging device, and more particularly to a printer assembly including a mechanism for automatic homing and rotating of a media stripper carriage.
2. Description of Related Art
In an imaging process an intermediate image is printed onto a print surface of a drum, the print surface generally having a release agent coated on the surface of the drum. The intermediate image is then transferred from the print surface onto a print medium, such as paper or transparency material, in a transfer fusing process. More specifically, the image is transferred onto the print medium by passing the medium between a drum having a surface and a transfix roller. Heat and pressure is applied to the medium in a contact region (pressure nip) between the drum and the roller such that the image is transferred from the drum to the medium. Such a transfer process causes the medium to tend to adhere to the surface of the drum. Thus, after a leading edge of the medium emerges from the pressure nip, the medium must be stripped from the drum and guided to the next set of transport rollers.
To strip the medium from the drum, strippers are generally used. For example, it is known to use multiple, spring loaded, plastic fingers that are presented to the drum and media at a specified point. A stripper may only contact the drum in a leading edge margin to avoid disturbing the fragile image that has recently been transferred to the media. The transfix stripper blade may be a passive stripper with constant engagement to the roller surface. When forming an image on both sides of the media (duplex prints) or, for example, when using a highly curled media, such as, for example, a light weight stock paper, the media may also “stick” to the transfix roller. Thus, a stripper may also be used in connection with transfix rollers. If there is any damage to the print medium, such as a bent corner, a bent leading edge, a cut in the media or any other blemish in the media, or error in the print process, the result may be a serious jam that is difficult to clear and may require an expensive service call.
Accordingly, in the event that maintenance of the printer is needed, or for any other reason, a user may have to remove the stripper from the device. For example, in the event that the media jams at the imaging drum, transfix roller, or elsewhere, a user may have to open the printer or copier to clear the jammed media before continuing use. Many times, in order to reach the jammed media, different parts of the device must first be removed and then returned after the jammed media is cleared.
For example, as described in U.S. Pat. No. 6,293,545 (herein incorporated by reference), a stripper blade assembly for removal of a print medium from an imaging drum of a printer is described. The stripper blade assembly uses a thin, durable, flexible blade and the assembly is removable and installable by a customer. The blade, that extends the width of the drum, is mounted on a blade holder. The blade holder is detachably mounted on a shaft having an over molded connector. The entire assembly rotates or otherwise moves to present the thin edge of the blade to the drum along the axial length of the drum in order to strip the leading edge of the print medium from the drum at the appropriate point in the print process. However, a customer is required to remove parts of the printer in order to reach an intended area of the printer to clear a jam and then must correctly replace the parts before being able to resume printing.
Likewise, in many common printers, a user is required to remove the stripper from the printer in order to gain access to a jam, or, for example, to clean the blade. After the stripper is removed, other parts of the printer may also pose an obstacle to reaching the jammed media.
After a user removes or moves the stripper and/or other parts, each of these parts must be re-installed or returned to its original location before the printer may be used again. Printers may not have a mechanism that would alert the user that all parts have not been properly re-installed. If all the parts are not re-installed or not re-installed correctly, the printer will jam again.
In other known printing systems, various parts of the printer, including the stripper, are not easily removable. Thus, a user must attempt to clear a jam, clean parts, or for whatever reason, work inside the printer without the benefit of being able to move parts that may be in the way.
Accordingly, the present invention provides a system and method wherein the stripper and other parts may be more easily reached for maintenance, cleaning, or the like, without removing parts of the printer or damaging the print media or the parts of the printer.